A system in which cables have been disposed in a lead-through chute is generally known. The known system is formed by coated mineral-wool plates which may be mounted around the lead-through chute in, for example, a lead-in aperture in a wall.
One drawback of the known system is that in actual practice it is often very difficult to mount these mineral-wool plates from the outside in the lead-in aperture, around the lead-through chute and round about the cables passed through the said aperture on account of their poor accessibility from the outside. A further drawback is that when additional new cables are inserted into existing lead-throughs provided with mineral-wool plates, considerable damage may be inflicted upon these plates. Moreover, the known system has the disadvantage that it can hardly, if at all, withstand mechanical loads, so that in the event of a fire a jet of fire-fighting water can easily thrust the coated mineral-wool plates out of the lead-in aperture.